Apparatus for making abrasive articles

ABSTRACT

Depositing abrasive particles, such as diamonds, silicon carbide, titanium carbide, aluminum oxide, or mixtures thereof, in a matrix of electrochemically deposited metals on the outer periphery and/or the adjacent marginal side portions of metal (or non-metals) blanks or wheels.

United States Patent Sam Aug. 5, 1975 [54] APPARATUS FOR MAKING ABRASIVE1,594,509 8/1926 Rosenquist 204/217 ARTICLES 3,046,204 7/1962 Barron204/16 3,281,996 11/1966 Cuk1anz..... 51/204 Inventor: Ahmad 462 n s3,488,892 1/1970 Benner et a1. 51/204 Paramus, NJ. 07652 3,619,38411/1971 Eisner 204/35 R 3.619.400 11/1971 Eisner 204/216 [221 Wed: 19743,666,636 5/1972 Tomaszewski et al.. 204/52 R [2}] pp No: 32 2 3.691,7079/1972 I Von AI'X 8t 31. 204/49 X Related Application Data PrimaryE.\'aminerF. C. Edmundson [62] Division of Ser. No. 87,177, Nov. 5 1970,Pat No. Anornev, Agent Fi Li1]i & Si

52] 11.5. C1. 204/217; 204/215; 204/1310. 10 1 ABSTRACT [5 CL":Depositing abrasive particles uch as diamonds ili 1581 held of Search H204/212 con carbide, titanium carbide, aluminum oxide. or

204/217 mixtures thereof, in a matrix of electrochemically depositedmetals on the outer periphery and/or the ad ja- 1 References C'ted centmarginal side portions of metal (or non-metals) UNITED STATES PATENTSblanks or wheels.

1.127 966 2/1915 Cowper-Coles 204/212 X 1513.1 19 10/1924 Madsen 204/212x 14 19 Drawmg figures APPARATUS FOR MAKING ABRASIVE ARTICLES Thisapplication is a divisional application of applicants prior pendingapplication, Ser. No. 87,177, filed Nov. 5, 1970. now US. Pat. No.3,785,938.

BACKGROUND OF THE INVENTION:

Abrasive grinding wheels heretofore have been made by either a sinteringprocess whereby the binding medium is metal or by a vitrified orclay-bonded process whereby wheels are made of fused clays. Other wheelsare made using a shellac bond, rubbcrbond or resinoid bond, however, noone bond makes the best wheel for a multitude of purposes. Generally,each type of bonded wheel has its particular fields of application.

In addition, grinding wheels can take the form of many shapes, butusually they are either of disk shape or cup shape. In the disk shapewheel, the effective abrasive grinding section extends entirely aboutthe periphery whereas in the cup shape wheel the effective diamondgrinding section extends about the outermost peripheral area. Withrespect to the present invention, we are generally concerned with agrinding wheel having a metal blank including a hub portion. The hubportion is usually provided with a central bore permitting same to bemounted on a shaft or spindle. The blank may suitably be of steel orother metal. Non-metal wheels suitable for electroplating may also beused. More specifically, it is what is carried on the periphery of thewheel in a position to make effective contact with a work piece withwhich the instant invention is primarily concerned. An effectivegrinding section which is the peripheral zone of the disc or wheelcommonly has an abrasive thickness of from mils to one fourth inch. Itis this section which includes the abrasive grinding material, and thepresent invention includes methods and apparatuses for making suchgrinding disks and wheels. The invention also pertains to methods andapparatuses for making grinding belts and slicing band saws.

Accordingly. it is an object of the present invention to provide novelmethods and apparatuses for making grinding wheels of disk shape and cupshape.

It is also an object of the invention to provide novel methods andapparatuses for making cutting wheels.

It is another object of the invention to provide novel methods andapparatuses for making grinding belts and band saws.

It is yet another object of the invention to provide novel methods andapparatuses for making side grinding wheels.

With the above and other objects in view which will appear as thedescription proceeds, the present invention resides in the novel methodsand apparatuses hereinafter described and more particularly defined bythe appended claims, it being understood that such changes in thespecific embodiments of the hereindescribed invention may be made ascome within the scope of the claims.

A better understanding of the invention will be had by the followingdetailed description when considered in connection and together with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a perspective view, partially broken away, illustrating acutting wheel made in accordance with the invention;

FIG. 2 is a perspective view, partially broken away, of a grinding wheelmade in accordance with the invention;

FIG. 3 is a front elevational view, partly in section, of one of theapparatuses for carrying out a process and method of the invention;

FIG. 4 is a sectional view, taken along the line 44 of FIG. 3;

FIG. 5 is a greatly enlarged view of the wheel fixture assembly, shownin FIGS. 3 and 4, for holding the core blank or base metal wheel uponwhich the abrasive (diamond) particles are deposited about itsperipheral edge;

FIG. 6A is a side view of a wheel, illustrating inert beads in amodified form of fixture so as to partially fill the beveled part of thegap or groove;

FIG. 6B is a side view of another wheel, similar to that shown in FIG.6A, illustrating a liquid to partially fill the beveled part of the gapor groove;

FIG. 7 is a sectional view of an apparatus similar to that shown in FIG.3, but with an idle roller so as to increase the length of wrap aboutthe grinding wheel;

FIG. 8 is a side elevational view, partly in section, of a grindingwheel, made in accordance with another method of the invention wherein acircular band or ring is employed in lieu of a long belt;

FIG. 9 is a sectional view, along the lines 99 of FIG.

FIGS. 10 and 11 are generally sectional views, and illustratrate sidegrinding wheels which can be made in accordance with the method andapparatus of FIGS. 8 and 9, or with the method and apparatus of FIGS.3-5;

FIG. 12 is a sectional view showing a cup shape wheel made in accordancewith either the method and apparatus of FIGS. 8 and 9, or FIGS. 3-5;

FIG. 13 is a sectional view representing a side grinding wheel made inaccordance with yet another method of the invention, wherein theelectrolyte is selfcontained within a cavity surrounding the area to beplated;

FIG. 14 is a sectional view similar to that of FIG. 13, except that acup shape wheel is shown;

FIG. 15 is a cross-sectional view of yet another embodiment of theinvention for making cutting or slicing band saws, by means of eitherthe method and apparatus of FIGS. 3-5, 7, or FIGS. 8 and 9;

FIG. 16 is a cross-sectional view of a further embodiment of theinvention, for making band saws by means of the method and apparatus ofFIGS. 13 and 14; and

FIGS. 17a and 17b are substantially sectional views illustrating anothermodification of the invention wherein abrasive grinding belts may bemade using a non-conductive inner wheel or blank, and the method andapparatus of either FIGS. 3-5, 7, or FIGS. 8 and 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring now to the drawings, and particularly to FIGS. 1 and 2respectively, there is illustrated typical cutting and grinding wheelsmade in accordance with the present invention. As shown in FIG. 1, thecutting wheel 10 has abrasive particles deposited on three sides of thewheel, i.e., the outer peripheral edge 12 and also along both adjacentmarginal outer side edges 14 and 16. The core or blank disc 18 ispreferably made of a metal, but if desired, it may be a non-metallicmaterial, such as plastic.

In FIG. 2, the grinding wheel has a core or blank 22 and a peripheralgrinding edge surface or section 24 provided only about the outer edgeof the blank.

Referring now to FIGS. 3-5 and 7, more particularly to FIGS. 3-5, thereis shown one apparatus for carrying out a method of the invention. Inthis arrangement, the grinding (or cutting) wheel 26 is disposed betweenopposed insulative plates or discs 28 and 30, preferably made of atransparent plastic such as lucite, polystyrene, polycarbonate, etc. soas to enable one to visually observe the work piece. The plates aresuitably clamped or otherwise locked together by means, such as atie-rod 32. The tie-rod 32 is preferably driven by a motor 34 throughsuitable coupling means 36, as best shown in FIG. 4'. Current carryingmeans, such as conventional spring loaded brushes 38 maintain contactwith thetie-rod 32 which in operation represents the cathode of theelectrolytic circuit of the invention.

In this particulararrangement wherein a belt 40 is employed, the upperwheel or roller 42 is used to provide tensioning to the belt. In thisconnection, a suitable tension adjustment may be provided, such as, forexample, by slotted apertures 44 and 46 in the rear wall A 47 andassociated bolts 48 and 50. Such device, of

course, provides the means for putting the belt about the rollers. Asbest shown in FIG. 3, the grinding wheel 26 is positioned withinsuitable tank means 52, preferably also made of a transparent material,such as glass, lucitc, or the like. The tank means 52 contains thenecessary electrolytic solution 54. It is also within the invention toemploy a tank with window means or with other means for monitoring ormaintaining perception of the deposit. The anodes which form part of theelectrolytic circuit are illustrated at 56 and 58 in FIG. 3. A curvedslot 60 is suitably provided in the rear wall 47 so as to permit theupper wheel 42 to be disposed at an angle with respect to the vertical.For example, with the assembly operating in a clockwise fashion, it ispreferable to have the upper wheel 42 disposed toward the right side ofthe curved slot 60. With the assembly operating counter-clockwise, it ispreferable to position the upper wheel 42 toward the left side of thecurved slot 60. The reason for such arrangement is that the belt 40covers a greater percentage of the peripheral edge of the wheel in thedirection which minimizes the possibility of the abrasive particles tobe carried beyond the wheel which is to be coated with abrasiveparticles to the upper wheel 42 by means of adhering to the belt 40.Also, such arrangement precludes such particles from dropping out of thecavity or gap 62 between the plates 28 and and the belt and falling tothe bottom of the tank 52.

As best shown in FIG. 7, a more preferred'arrangement off the apparatusis illustrated. As shown therein, the belt 40 is wrapped about thegrinding wheel assem bly 63 for about 270 by means of an arrangement,such as a tension idle roller 64. The roller 64 eliminates the need forproviding adjustment to the upper roller or wheel 42 and such anarrangement, minimizes the adherence of abrasive particles to the belt40 and from being carried to the upper wheel. Also, this set-upprecludes the particles from dropping to the bottom of the tank 52 sincethe abrasive particles are retained in the gap 62 for about 270. Ifnecessary, a plurality of idle rollers may be employed. In operation, aswill be described hereinafter, it will be appreciated that the abrasiveparticles due to gravity primarily stay near the bottom'of the grindingwheel assembly and in an imaginary quadrant in the direction of rotationof the grinding wheel assembly.

As best shown in FIG. 5, suitable insulative cover means 66 and 68fastened respectively to the insulative plates or discs 28 and 30protect the tie rod 32 and its associated nuts from also being platedwith the depositing metal. If desired, suitable sealing means, such asan O-ring (not shown) may be provided about the tie rod 32 which extendsoutwardly from the grinding wheel 26 for connection with the motormeans. In addition, a suitable seal or packing, such as a nylon bushing72 with associated O-rings seals the tie rod 32 where it passes throughthe rear wall of the tank means 52 (see FIG. 4). Likewise, if desired,suitable O-rings or rubber gaskets may be placed between cover means 66and disc 28, and between cover means 68 and disc 30 to prevent theleakage of the electrolyte to the wheel fixtures.

In operation, a matrix of metal and discrete abrasive particles, such asdiamond grains, is deposited on the desired surfaces of the wheel. Themetal which is the carrier for the abrasive particles iselectrolytically deposited on the wheel by means of a suitable circuitarrangement, such as'a DC circuit wherein the grinding wheel 26 is thecathode and the deposited or bonded metal represents the anode. In theapparatus of FIGS. 3 and 4, the metal to be deposited is illustrated aselectrodes 56 and 58. Such electrodes represent the anodes for thecircuit and the cathode comprises the tie rod 32 andthe grinding wheel26 which is in intimate electrical contact therewith.

The electrolytic solution, of course, depends upon the metal to bedeposited. For example, where nickel is the carrier metal, a preferredelectrolyte is nickel sulphamate solution [Ni(So NI-I containing desiredadditives, such as a buffering agent, wetting agent, etc., which providea suitable nickel deposit. With nickel, the preferred temperature rangeof the electrolytic solution is from about 40-70C (102160F). As ageneral rule, temperatures above or below such preferred range givepoorer quality of end product.

The current input of the DC power supply is preferably within the rangeof about 10-30 ASF of apparent surface. The rate of deposition of themetal is controlled by the current density, and it should be noted thathigher densities give poor quality of the deposited metal, whereas atlower densities than 10 ASF fewer particles are embedded in the metalbecause insufficient metal is deposited on the wheel.

The concentration of abrasive particles in the matrix may also becontrolled by varying the amount of the abrasive in contact with thewheel, the particle size, the current density, the speed of rotation ofthe wheel and by whether or not the mode of rotation of the wheel isinterrupted or continuous.

With respect to particle size, the smaller the particles, the higher theconcentration; and with respect to current density, the higher thecurrent density, the lower the concentration. Too low current densitiesalso lower the abrasive concentration by precluding sufficient build-upoff the deposited metal which is necessary to adequately anchor and holdthe abrasive particles in place.

With respect to the speed of rotation, the higher the speed, the lowerthe concentration of particles. In addi tion, where the mode ofoperation of the wheel is one of interrupted rotation, the higher theconcentration of particles.

Preferably. the electrolyte is stirred or air agitated during operationor otherwise circulated so as to provide a uniform deposition of themetal and so that the deposited metal is replenished on the cathode.

With respect to operational procedures, as the cutting-grinding wwheelassembly rotates, the abrasive particles move in the gap 62 about theperipheral surface of the wheel to be plated and gradually as the metalis deposited, particles are bonded therewith and built up uniformallyabout the periphery of the wheel. The build up of the deposited metaland particles is achieved in a sense by the cumulative effect ofbuilding up layers.

It will be appreciated that the belt 40 is preferably made of an inertnon-conductive material, such as thermoplastics, rubber, coated metals,etc. It could be either porous or nonporous to the electrolyte. Apreferred speed of rotation of the grinding wheel assembly is about 0.05to 0.25 rpm. A more preferred. rate is about 0.2 rpm. Of course, thetemperature of the elecyrolytic solution may be maintained by suitableimersion heaters (not shown). With respect to the size of the abrasiveparticles, such as diamond grains, particles ranging from about l6 meshto about 600 mesh (1 190 micron to 30 micron) are suitable.Theoretically, all commercially available sizes could be utilizedalthough the above range is preferable. In a like manner, the inventionis applicable to any size blank or wheel diameter, as well as thickness.For example, wheel diameters as large as about 8 inches have beenutilized and wheel thicknesses as thin as a few thousandths of an inchhave been utilized by the method and apparatus of the inventi n toproduce commercially acceptable abrasive wheels, such as diamondgrinding wheels.

In FIGS. 6A and 6B, there is shown modifications of the process whereinsuitable beads 74, such as glass beads, are employed in the beveled partof the gap area so as to aid in filling the space between thenonconductive plates handling the sandwiched wheel. In FIG. 68. asuitable liquid, such as mercury 76, may be employed to cause floatationof the abrasive particles so as to facilitate the electro-platingprocess and aid in urging the abrasive particles toward the wheelsperipheral surfaces to be plated.

In FIGS. 8 and 9, an alternate apparatus is illustrated wherein the belt78 is an elastic band in a partly stretched condition which completelyencircles the wheel assembly which includes the blank 80 and the outerplates 82 and 84 held together by suitable tie rod means 86. In suchconstruction, the belt 78 which is porous permits the electrolyticsolution to pass therethrough. The abrasive particles are retained inthe gap 88 and such overall assembly may be utilized in the tank means52 of the apparatus of FIGS. 3, 4 and 7. As best shown in FIG. 8, afluid jet 90 may be employed for directing a stream of fluid, preferablythe electrolytic solution itself to the wheel assembly so as to promotemore uniform plating of the wheel being made and to aid in providinguniformity of concentration of the abrasive particles about theperipheral surface of the wheel. Such a fluid jet is preferred inapplications where the ratio of wheel thickness to size of abrasiveparticle is small. The method and apparatus of FIGS. 8 and 9 arepreferred where thin wheels of the order of about 0.003 inch to about0.125 inch are desired,

whereas the method and apparatus of FIGS. 3-5 and 7 lends itself and isbetter suited for thicker grinding wheels.

lillustrated in FIGS. 10 and 11 is a side grinding wheel 92 comprising ametal blank having its outer marginal or peripheral edge 94 suitablyplated and coated with the abrasive particles retained in the gap orspacing 96 between the blank and one of the nonconductive plates 98 and.100 forming the sandwiched wheel assembly. The assembly, in a likemanner as indicated hereinbefore in connection with the wheel assemblyof FIGS. 35, is suitably held together by a tierod 102 and associatedhardware, such as the end nut 104. It will be appreciated that such sidegrinding wheel 92 can be made using either the method and apparatus ofFIGS. 8 and 9, or the method and apparatus shown in FIGS. 3-5 and 7. Itwill be appreciated that the abrasive coated marginal side area 94 ofthe wheel 92 may be varied by changing the size of the gap or spacing96. If desired, the gap can be increased to cover the entire sidesurface of the wheel 92. In a like manner, FIG. 12 illustrates and showsanother arrangement wherein a cupshaped grinding wheel 106 is made witha similar fixture assembly. Of course, with such arrangement, theabrasive particles are deposited on the outer peripheral side edge 108of the cup-shaped blank.

With reference to FIGS. 13 and 14, a further method and apparatus of theinvention is illustrated wherein the electrolytic solution isself-contained within a cavity provided in the fixture or wheelassembly. As shown in FIG. 13, a metal blank 110 is suitably fixedlydisposed between non-conductive elements 112 and 114 formingtherebetween a cavity 116 for the electrolytic solution 118. Suchassembly, of course, is suitably held fixedly together in a leakproofmanner by suitable clamping means (not shown) disposed about theperipheral marginal edge. For example, suitable nuts and bolts may beprovided about flanges extending radially outwardly from the joint area.The central core area 122, including the shaft or rod and associated nutholding the blank 1 10 to theelement 112, is masked off by means of asuitable non-conductive coating 124 which may be applied by brushing iton or the coating may simply be some sort of a masking tape. It shouldbe noted that due to gravity, the abrasive particles are retained in thegap or area 126 formed between the two elements 112 and 114. With suchapparatus, the amount of abrasive particles to be deposited should beprovided in place in sufficient quantity at the start of the process sothat the fixture need not be resupplied during operation which mayentail disassembly of the unit. If desired, suitable means (not shown)may be provided for adding additional particles during use and withoutthe need for disassembly. Suitable anode means is shown at 127 and sameis held to the element 114 by means of the shaft 120, which is hollow inconstruction, and a cooperatively associated nut 131. Inasmuch as gasesare released during the operation of the apparatus, suitable vent means133, in the form of a tube or pipe, extends from above the electrolytelevel to the atmosphere so as to vent such gases from the free spaceabove the level of the electrolyte. The apparatus of FIG. 14 illustratesa similar assembly for use in making cup-shaped wheels 128. Of course,with such" structure, the masked off portion comprises not' only' thecentral core area 130,'but also the inner peripheral edge portion 132adjacent the outer peripheral side edge 134 being coated.

In FIG. 15, there is shown a slicing band saw 136 having abrasiveparticles deposited along an edge 137 thereof. In such a construction,electrical contact is made at the band saw 136 by means of a springloaded contact pin or red assembly. The spring 138 is disposed betweenthe conductive tie-rod 140 and the contact rod 142. The abrasiveparticles are, of course, suitably disposed within the gap 144 formedbetween the nonconductive elements 146 and 148. This assembly mayobviously be employed with either the method and apparatus of FIGS. 35,7 or with the method and apparatus of FIG. 8 and 9. The belt 150, as inthe other embodiments, is suitably maintained in place by a peripheralgroove or recess 152 formed in and by the elements 146 and 148.Alternatively, the belt may be replaced by a porous elastic or rigidring as shown in FIGS. 8 and 9.

In FIG. 16, a cutting band saw 154 is made by means of the method andapparatus of FIGS. 13 and 14. The fixture assembly, that is members 156,161 and 163 are made of a nonconductive material, preferably atransparent plastic or the like. Special contact means, such asdescribed hereinafter with respect to FIG. 17a con nect the band saw 154to the cathode of the power source. As in the case of the band saw ofFIG. 15, abrasive particles which are retained in the gap 158 aredeposited on the edge 160 of the band saw blade being formed. Such bandsaws of the invention are therefore provided with a uniformly depositedcutting edge capable of cutting or slicing through many materials whichare very difficult to cut, such as glass, ceramic elements, hard metalsand alloys thereof, masonry, carbides, aluminum oxide, quartz, or thelike.

FIGS. 17a and b further illustrate yet another modification of theinvention wherein grinding belts can be made by either the method andapparatus of FIGS. 35 and 7, or that shown in FIGS. 8 and 9. Thegrinding belt shown as 162, preferably made of a thin metal sheet,

such as stainless steel, bronze, etc., is disposed about a suitable corewheel 164, preferably of a nonconductive material, such as plastic. Thegrinding belt 162 is retained in place by means of the end plates 166and 168, and in this particular arrangement, a complete porous belt 170is positioned about the end plates 166 and 168. Of course, with themethod and apparatus of FIGS. 3-5 and 7, the belt need not necessarilybe of the porous type and it would be longer inasmuch as it must bedisposed over other wheels, such as the wheel 42 of FIGS. 3 or 7. In theembodiment shown herein, electrical contact is made with the conductivetie-rod 172 by means of a suitable contact rod 174 and a compressionspring 176 positioned between the rod 174 and the tierod 172. A gap 178between the outside belt 170 and the grinding belt 162 contains theabrasive particles to be deposited on the wide outer surface 180 of thegrinding belt 162.

In the alternate embodiments of the invention wherein a porous belt orring is employed, suitable elastic material, such as a woven ornon-woven band or tape may be used. For example, one such material whichprovides excellent results is a woven stretchable elastic compositionalmaterial having about 29% rubber and 71% nylon. If necessary, thisstretchable elastic may be lined with a suitable micro-porous filtercloth particularly where the abrasive grains are too small (-170 mesh orsmaller) to retain the particles. Other types of materials which alsomay be employed in the practice of the invention are porous porcelain,porous clay or ceramic, and porous plastic, etc. Such material would, ofcourse, form a rigid band or ring but otherwise would perform nodifferent than an elastic porous band or ring.

Although not shown herein, it is within the scope of this invention,that the gap between the plates or elements of the wheel assembliescontaining the abrasive particles can be formed by other configurations,such as a groove or recess within the belt itself. However, with thearrangements illustrated herein, a uniform and constant depth of depositis assured. The gaps shown herein may also be V-shape in form or bebeveled, if desired, so as to facilitate migration of the abrasiveparticles within the space or gap between the plate elements.

It will be appreciated that the abrasive material used in the practiceof the invention is generally natural or synthetic diamonds betweenabout 16 and about 600 mesh (1 micron to 30 micron). Other synthetic ornatural abrasive materials such as silicon carbide, titanium carbide,tungsten carbide, boron nitride, titanium diboride, and aluminum oxidecan also be used in the practice of the invention. A mixture of diamondsand less expensive abrasives may be desired and such mixture would alsobe efficient as well as more economical. If desired, non-abrasive grainssuch as mica or molybdenum disulfide may be mixed with the abrasives forspecial reasons such as reducing friction, etc.

It should also be understood that the addition of abrasive particles,such as diamonds, to the cavity surrounding the blank wheel or belt isdone at any stage during the formation of the peripheral matrix.Generally, it is done after the electrolyte is added to the tank orother cavity holding same, and thereafter as the supply of the abrasiveparticles diminishes, a slurry is made up of the electrolyte and theabrasive particles and same is transferred to the cavity between thebelt 40 and the plates 28 and 30 of FIG. 4 with a suitable dispenser (ora glass or plastic funnel), such as a medicine dropper. In the apparatusof FIGS. 8 and 9, the elastic ring or belt 78 is slid off the gap 88 onthe top portion, and the abrasives are added. The belt is then restoredto its proper position so that the apparatus is then ready for use.

As a general rule, from about oneeighth to about one-fourth of the spacebetween the plates is filled with the abrasives for the apparatus ofFIGS. 3, 4, 7, 8 and 9 and more if it is added as it is deposited. If arigid ring is used or the embodiments of FIGS. 13, 14 or 16 areemployed, then the abrasives should be introduced all at once in dryform at the time the assembly is put together. Visual observation of theabrasive movement and the progress of the matrix formation isaccomplished by employing a suitable light source in back of the wheelassembly and observing through the trans parent walls of the tank andthe plates 28 and 30. The movement of the abrasive is most interestingin that due to gravity, etc. they tend not to travel beyond the quadrantin which they are disposed.

The following examples are illustrative of wheels of the types shown inFIGS. 1 and 2 and made in accordance with the principles of theinvention. The abrasives used in all of the following examples werenatural diamonds. In examples I, 2, 5 and 6, the apparatus of FIGS. 8and 9 was employed. In example 5, the appara EXAMPLE NO Continued tus ofP168. 35 was used; and in example 6, the appa- I I both sides) 0.055"ratus of FLG. 7 was used. The rotation was continuous Dcpm of matrix(bonded deposit) at 0.2 rpm in examples 1, 2 and 6 and it wasinterrupted Current 90 ma a 0.1 r m in exam les 3, 4 and 5. Time 205 t pp 5 Particle size /2 40-50 mesh EXAMPLE NO. 1. 50-60 mesh Weight ofdiamond used 2.595 grams Volume of matrix 0.169 in" or 2.77 cm Wheel(disc) diameter 4.763" Percentage of diamond by volume 27% Wheelthickness 0.016" Cathode efficiency 90% Wheel thickness at cutting edge(ineludes thickness and deposit on both sides) 0.020" Depth of matrix(bonded deposit) 120 mils. EXAMPLE NO 6 Current 20 ma. Time 196 hrs.Weight of abrasives (diamond) used. 0.580 grams whee] diameter 4Particle (diamond) size /2 60 80 mesh. wheel thickiLess 0.008

80 100 mesh. 1 3 Wheel thickness at cutting edge Volume of matrix 0.0359in. l d d Volume of diamond 0.0100 in." L i Percentage of diamond byvolume 27% 0th S volume of Nickel 00259 in Depth of matrix (bondeddeposit) 0.054 Cathode efficiency 90% CPrrem ma Time 76 hrs.

Particle Size (diamonds) 140-170 mesh Weight of diamond used 0.208 gramsVolume of matrix 0.160 cm EXAMPLE Volume of the diamond 0.0592 cmPercentage of diamond 37% fi Wheel Diameter 4.763" Cathode 6 92% Wheelthickness 00m" Wheel thickness at cutting edge (in "Ckncswf dclms bmh oIt should be noted that the above-described exam- .1 C t Depth of matrix(bonded deposit) 62 mils. ples, modifications and embodiments of theinvention gurwm g are not to be construed as specifically limiting theinfSi ra of abrasive (diamond) 56 0300 grams vention to the precise anddetailed specific structures Particl (diam nd) i 1;: g tyler shown inthe figures and as described herein. Actually, vulumc of matrix a gfl gfi a variety of constructions and arrangements for making Volume ofdiamond 0.0052 in." such metal bonded abrasive elements may be employedgg ii by Plume 5 6 in 3 and all such, within the broad scope andteachings of Cathode efficiency 91% the present invention, are intendedto be included and EXAMPLE NO. 3.

EXAMPLE NO. 4.

Wheel diameter 4%" Wheel thickness /ii" Depth of matrix 47 mils. Current0.14 amperes Time 50 hrs.

325-400 mesh 2.5 grams 12.5 karats) Particle Size (diamonds) Weight ofdiamonds Volume of matrix 1.476 cm Volume of diamonds 0.712 cm"Percentage of diamond 48.2% Weight of carrier (nickel) 6.80 gramsCathode efficiency 90% EXAMPLE NO. 5.

Wheel diameter wheel thickness Wheel thickness at cutting edge (includesthickness and deposit on comprehended herein. For example, in specialapplications the matrix may contain discrete non-abrasive particleshaving certain properties, such as catalytic, semiconductivity,radioactivity, fissionability, explosiveability, fluoresence, etc.

What is claimed is:

1. An apparatus for the manufacture of an abrasive element, on basemeans, having a continuous area of metal bonded abrasive material platedor bonded to at least one surface thereof in an electrolytic soluctionof metallic ions comprising: a pair of non-conductive elements disposedon opposite sides of said base means so as to define a space or gapabout said surface to be plated; an endless, inert belt means,encircling at least a portion of said pair of non-conductive elementsand maintaining a zone or gap between said pair of nonconductiveelements and said base means, for retaining therebetween in closeproximity to said surface a concentration of abrasive particles; meansrotating said base means at least periodically so as to expose thesurface of said base means to which abrasive material is to be bonded;and means for maintaining a current in said solution to effect theelectro-deposition of said abrasive particles on to said surface at apredetermined rate.

2. The apparatus according to claim 1 wherein said endless, inert beltmeans completely encircles said base means and said pair ofnon-conductive elements.

3. The apparatus according to claim 1, wherein said endless, inert beltmeans comprises the means for rotating or driving said base means.

4. The apparatus according to claim 3, including a shaft rotatable byseparate drive means in said belt means encircling said shaft forrotating said base means.

5. The apparatus according to claim 1, wherein said endless belt meansis porous.

6. The apparatus according to claim 1, wherein said endless belt meansis elastic.

7. The apparatus according to claim 1, wherein said base means is thecathode for the electrolytic solution and an electrode of the metal tobe deposited in said solution comprises the anode.

8. The apparatus according to claim 1, wherein means for rotatingprovides for an interrupted or discontinuous form of rotation.

9. The apparatus according to claim 1, wherein said means for rotatingprovides for the continuous rotation of said base means.

10. The apparatus according to claim 1, wherein said current is of thedirect current type.

11. The apparatus according to claim 1, including means for stirring orcirculating said solution during operation.

12. The apparatus according to claim 1, wherein said abrasive materialcomprises abrasive particles ranging in size from about 16 mesh to about600 mesh, and the metal bonded abrasive material deposited comprisesnickel and diamonds.

13. The apparatus according to claim 1, wherein the electrolyticsolution comprises nickel sulfamate maintained at a temperature fromabout 40 C. to about C.

14. The apparatus according to claim 1, wherein the current in saidsolution is from about 10 to about 30 amperes per square foot ofapparent surface, and said base means is rotated within the range0.05-0.25 r.p.m. l l l

1. AN APPARATUS FOR THE MANUFACTURE OF AN ABRASIVE ELEMENT, ON BASEMEANS, HAVING A CONTINUOUS AREA OF METAL BONDED ABRASIVE MATERIALPLEATED OR BONDED TO AT LEAST ONE SURFACE THEREOF IN AN ELECTROLYTICSOLUCTION OF MATELLIC ION COMPARISING: A PAIR OF NON-CONDUCTIVE ELEMENTSDISPOSED ON OPPOSITE SIDES OF SAID BASE MEANS SO AS TO DEFINE A SPACE ORGAP ABOUT SAID SURFACE TO BE PLATED, AN ENDLESS, INERT BELT MEANS,ENCIRCLING AT LEAST A PORTION OF SAID PAIR OF NON-CONDUCTIVE ELEMENTSAND MAINTAINING A ZONE OR GAP BETWEEN SAID PIR OF NON-CONDUCTIVEELEMENTS AND SAID BASE MEANS, FOR RETAINING THEREBETWEEN IN CLOSEPROXIMITY TO SAID SURFACE A CONCENTRATION OF ABRASIVE PARTICLES, MEANSROTATING SAID BASE MEANS AT LEAST PERIODICALLY SO AS TO EXPOSE THESURFACE OF SAID BASE MEANS TO WHICH ABRASIVE MATERIAL TO BE BONDED, ANDMEANS FOR MINTAINING A CURRENT IN SAID SOLUTION TO EFFECT THEELECTRO-DEPOSITION OF SAID OBRASIVE PARTICLES ON TO SAID SURFACE AT APREDETERMINED RATE.
 2. The apparatus according to claim 1 wherein saidendless, inert belt means completely encircles said base means and saidpair of non-conductive elements.
 3. The apparatus according to claim 1,wherein said endless, inert belt means comprises the means for rotatingor driving said base means.
 4. The apparatus according to claim 3,including a shaft rotatable by separate drive means in said belt meansencircling said shaft for rotating said base means.
 5. The apparatusaccording to claim 1, wherein said endless belt means is porous.
 6. Theapparatus according to claim 1, wherein said endless belt means iselastic.
 7. The apparatus according to claim 1, wherein said base meansis the cathode for the electrolytic solution and an electrode of themetal to be deposited in said solution comprises the anode.
 8. Theapparatus according to claim 1, wherein means for rotating provides foran interrupted or discontinuous form of rotation.
 9. The apparatusaccording to claim 1, wherein said means for rotating provides for thecontinuous rotation of said base means.
 10. The apparatus according toclaim 1, wherein said current is of the direct current type.
 11. Theapparatus according to claim 1, including means for stirring orcirculating said solution during operation.
 12. The apparatus accordingto claim 1, wherein said abrasive material comprises abrasive particlesranging in size from about 16 mesh to about 600 mesh, and the metalbonded abrasive material deposited comprises nickel and diamonds. 13.The apparatus according to claim 1, wherein the electrolytic solutioncomprises nickel sulfamate maintained at a temperature from about 40* C.to about 70* C.
 14. The apparatus according to claim 1, wherein thecurrent in said solution is from about 10 to about 30 amperes per squarefoot of apparent surface, and said base means is rotated within therange 0.05-0.25 r.p.m.